There is a bulb-type lamp that can replace an incandescent lamp and in which an LED element is used as a light source. In the bulb-type lamp, a substrate on which the LED element is mounted and the light source is formed is attached to one end face of a base body and a globe that covers the light source is attached to one end of the base body.
In general, the incandescent lamp has a wide-angle luminous intensity distribution characteristic with high luminous intensity in both an optical axis direction and a direction crossing the optical axis direction. However, the bulb-type lamp has a luminous intensity distribution characteristic with high luminous intensity in an optical axis direction opposed to the front of the light source and low luminous intensity in a direction crossing the optical axis direction. Therefore, the use of the bulb-type lamp is unsuitable depending on a luminaire.
Therefore, it is ideal that, like the incandescent lamp, the bulb-type lamp has the wide-angle luminous intensity distribution characteristic with the high luminous intensity in both the optical axis direction and the direction crossing the optical axis direction. In the bulb-type lamp, diffusibility is often imparted to the globe that covers the light source. However, with the diffusion by the globe, it is difficult to obtain sufficient improvement of luminous intensity in the direction crossing the optical axis direction.
Therefore, in some bulb-type lamp, a lens is arranged to be opposed to the light source, light traveling from the light source in the optical axis direction is reflected to the direction crossing the optical direction by the lens to improve the luminous intensity in the direction crossing the optical axis direction.